Water from the mountains of Greater Central Asia
The lowlands of Greater Central Asia are dry: steppe, semi-deserts and deserts. The main reasons for the aridity are predominant westerly winds and lee-side effects, which cause very low precipitation sums (less than 100 mm per year) in the desert regions of Gobi, Karakum and Taklamakan. As a consequence of this aridity, Greater Central Asia consists of several so-called endorheic basins, which means that their runoff does not reach the ocean, but evaporates in the dry environment. Mountains are the water towers in the region; due to orographic effects, they receive annual precipitation sums of 1000–2000 mm. Greater Central Asia is a well-known example of a region that strongly depends on runoff formed in mountain regions (Viviroli et al., 2007).